User's Manual

MPR/MIB User’s Manual
Doc. # 7430-0021-07 Rev. B Page 21
7 Radios
7.1 MICA2 and MICA2DOT
7.1.1 Radio Considerations
The radio on the MICA2 and MICA2DOT is capable of multiple channel operation, within the
intended band of operation. The MPR420/MPR520 can span up to 4 channels of operation in the
315 MHz band, the MPR410/MPR510 can span up to 4 channels of operation in the 433 MHz
band (433.05–434.79 MHz). The MPR400/MPR500 can operate in two frequency regions: 868–
870 MHz (up to 4 channels) and 902–928 MHz (up to 54 channels). The actual number of
possible channels is higher for all the MICA2/MICA2DOT motes. However, it is recommended
that the adjacent channel spacing should be
at least 500 kHz to avoid adjacent channel
interference thereby reducing the number of available channels. A tutorial on how to change
frequency is available at http://www.tinyos.net/tinyos-1.x/doc/mica2radio/CC1000.html
.
7.1.2 Radio Transmission Power
The radio on the MICA2/MICA2DOT can be adjusted for a range of output power levels. The
register in the radio that controls the RF power level is designated PA_POW at address 0x0B,
and the values and their corresponding RF outputs are provided on Error! Reference source not
found. below. It shows the closest programmable value for output powers in steps of 1 dBm. For
power down mode the Chipcon datasheet says, “the PA_POW should be set to 00h [0x00] for
minimum leakage current.”